A North Canterbury farmer could be sent to jail for breaching a court order preventing him from causing ongoing damage to protected rare woodland.

The High Court in Christchurch last week ruled in favour of the QEII National Trust after it took Netherland Holdings Limited and director Roelof Wobben to court for breaching an injunction to prevent additional damage to the land while the action was before the court.

In 2012, NHL bought the Waimakariri farm which had covenants protecting areas of the land registered on its title.

According to the trust, NHL removed fences and destroyed about 2.4ha of legally protected indigenous trees and shrubs, leaving only a small section of protected land untouched.

Trust chief executive Mike Jebson said this would help NHL convert dryland farm to irrigation.

NHL's actions had "severely damaged" one of the last remaining pockets of undisturbed kanuka woodlands on the Canterbury Plains.

Once the trust discovered this, NHL said no further damage would be done to the protected areas.

Late last year the trust secured an injunction ruling NHL had breached the agreement.

However, this year, it took Wobben and NHL to court for breaching this injunction.

Jebson said the trust would defend the covenant agreement and secure the restoration of the rare woodland remnant.

In a written decision this week, Judge Rachel Dunningham found the defendants in contempt of court by allowing irrigators to pass through and/or water the covenanted land, and allowing fertiliser to be spread without taking precautions to stop it spreading on to covenanted areas.

"I have no doubt that this was conduct which was wilful, reckless or contumacious on the part of the defendants," she said.

"Mr Wobben should be in no doubt that imprisonment is an available option to punish a wilful or reckless disobedience of a court order".

Dunningham said an aggravating feature of this case was how the trust had to escalate its response to the alleged breaches of the covenants from informal advice, to formal undertakings and then to the courts.

The case seeking full restoration of the covenanted areas is still to be heard in the High Court.